1. Field of the Invention
The present invention relates generally to a glass door having a handle system for releasing a door latch, and, more particularly, to a door having an opening system of the "panic" type mounted on a glass door panel and suitable for use in releasing a look attached to an edge of the glass door.
2. Description of the Prior Art
Building codes and other safety regulations normally require that locked doors within offices and other facilities include a quick release or "panic" latch, allowing persons within the interior of the facility to readily open the door by simply pushing on an interior handle. From the exterior, however, the door latch or lock is released by a key, key pad, or other controlled lock release means. The lock may be a mechanical lock, a magnetic lock or an electro-mechanical lock, such as a lock operable by a solenoid. With these latter two locks, the release is effected by a change in current within a circuit which includes the lock.
Various panic-type door handles are known in the prior art. For example, U.S. Pat. No. 4,711,480 to Horgan, Jr., discloses a door handle having a horizontal component and a vertical component extending upwardly from the horizontal component to a pivotal attachment near the top of the door. A locking mechanism, which may be mechanical or magnetic, extends outwardly from the top of the vertical component and into engagement with the door frame. When the horizontal component of the handle is moved toward the door, a mechanical linkage within the vertical component of the handle withdraws the latching mechanism from the door frame, permitting the door to be opened.
U.S. Pat. No. 4,895,399 to Horgan, Jr. describes another kind of mechanically operable panic handle, in which one end is pivotally attached to the door. A pivotal latch having an outer position and an inner position is mounted on the door, and engages the door frame when in the extended position. Pushing on the door handle presses the unattached end of the handle against the latching mechanism, withdrawing it from engagement with the door frame.
Mechanical devices as illustrated by the above inventions are complex to manufacture and, therefore, difficult to maintain. A much less complicated release device with no moving parts, and thus very low maintenance, is described in U.S. Pat. No. 4,871,204 to Cooke, et. al., which uses a lock including an electromagnet mounted on the door frame to engage a striker plate mounted on the door. The electromagnet is in a sensor circuit which is responsive to changes in capacitance, along with a switch , a power source and a conductive door handle. When a person desiring to open the door touches the door handle, the capacitance within the circuit is changed, deactivating the electromagnetic lock. The Cooke et al door has gained commercial success. The mechanism, however, is only usable on certain door structures which have a frame for mounting the release mechanism. Specifically, as described in the sales brochure from Securitron, the assignee of the Cooke et al patent, the door can be an aluminum frame door, a hollow metal door, or a wood door.
Of considerable commercial importance is the fact that the Cooke et al invention, is not applicable to solid glass doors, i.e., doors including a glass panel without a frame or edging around its periphery. Doors of this construction, however, are of increasing use in the building trades, and a need exists for a latch release system for these solid glass doors that is both functional and attractive.
Thus, there remains a need for a new and improved solid glass door having a latch or lock component mounted on an edge thereof and a release mechanism mounted on the glass door panel adapted to release the lock when the release mechanism is contacted by a person seeking to open the door.